我想录制现场音频并播放它。就UI而言，应用程序只有三个按钮：一个用于开始录制和流式传输，一个用于播放预录制文件，最后一个用于停止当前录制文件任务（录音/播放）。为此，我分别使用 AudioRecord 和 AudioTrack 类进行录制和播放。我的程序看起来像......
/ ** * @author amit * * /
public class AudioRecorder extends Activity {
private String LOG_TAG = null;
/* variables which are required to generate and manage the UI of the App */
// private RecordButton mRecordButton = null;
private Button recordBtn, stopBtn, playBtn;
/*
* variables which are required for the actual functioning of the recording
* and playing
*/
private AudioRecord recorder = null;
private AudioTrack player = null;
private AudioManager audioManager = null;
private int recorderBufSize, recordingSampleRate;
private int trackBufSize;
private short[] audioData;
private boolean isRecording = false, isPlaying = false;
private Thread startRecThread;
private AudioRecord.OnRecordPositionUpdateListener posUpdateListener;
/**
* constructor method for initializing the variables
*/
public AudioRecorder() {
super();
LOG_TAG = "Constructor";
recorderBufSize = recordingSampleRate = trackBufSize = 0;
// init function will initialize all the necessary variables ...
init();
if (recorder != null && player != null) {
Log.e(LOG_TAG, "recorder and player initialized");
audioData = new short[recorderBufSize / 2]; // since we r reading shorts
} else {
Log.e(LOG_TAG, "Problem inside init function ");
}
posUpdateListener = new AudioRecord.OnRecordPositionUpdateListener() {
int numShortsRead = 0;
@Override
public void onPeriodicNotification(AudioRecord rec) {
// TODO Auto-generated method stub
// String LOG_TAG = Thread.currentThread().getName();
// Log.e(LOG_TAG, "inside position listener");
audioData = new short[recorderBufSize / 2]; // divide by 2 since now we are reading shorts
numShortsRead = rec.read(audioData, 0, audioData.length);
player.write(audioData, 0, numShortsRead);
}
@Override
public void onMarkerReached(AudioRecord recorder) {
// TODO Auto-generated method stub
Log.e(LOG_TAG, "Marker Reached");
}
};
// listener will be called every time 160 frames are reached
recorder.setPositionNotificationPeriod(160);
recorder.setRecordPositionUpdateListener(posUpdateListener);
Log.e(LOG_TAG, "inside constructor");
}
private void init() {
LOG_TAG = "initFunc";
// int[] mSampleRates = new int[] { 8000, 11025, 22050, 44100 };
short audioFormat = AudioFormat.ENCODING_PCM_16BIT;
// for (int rate : mSampleRates) {
this.recordingSampleRate = AudioTrack.getNativeOutputSampleRate(AudioManager.STREAM_MUSIC);
try {
// Log.d(LOG_TAG, "Attempting rate " + rate + "Hz, bits: " +
// audioFormat);
int bufrSize = AudioRecord.getMinBufferSize(this.recordingSampleRate,
AudioFormat.CHANNEL_IN_MONO, audioFormat);
// lets find out the minimum required size for AudioTrack
int audioTrackBufSize = AudioTrack.getMinBufferSize(this.recordingSampleRate,
AudioFormat.CHANNEL_OUT_MONO, audioFormat);
if (bufrSize != AudioRecord.ERROR_BAD_VALUE
&& bufrSize != AudioRecord.ERROR) {
// check if we can instantiate and have a success
if(audioTrackBufSize >= bufrSize){
this.recorderBufSize = audioTrackBufSize;
}else{
this.recorderBufSize = bufrSize;
}
AudioRecord rec = new AudioRecord(
MediaRecorder.AudioSource.DEFAULT, this.recordingSampleRate,
AudioFormat.CHANNEL_IN_MONO, audioFormat, this.recorderBufSize);
if (rec != null
&& rec.getState() == AudioRecord.STATE_INITIALIZED) {
// storing variables for future use . . .
// this.recordingSampleRate = rate;
// this.recorderBufSize = bufrSize;
Log.e(LOG_TAG,
"Returning..(rate:channelConfig:audioFormat:recorderBufSize)"
+ this.recordingSampleRate + ":" + AudioFormat.CHANNEL_IN_MONO
+ ":" + audioFormat + ":" + this.recorderBufSize);
// Now create an instance of the AudioTrack
// int audioTrackBufSize = AudioTrack.getMinBufferSize(rate,
// AudioFormat.CHANNEL_OUT_MONO, audioFormat);
Log.e(LOG_TAG, "Audio Record / Track / Final buf size :" + bufrSize + "/ " +audioTrackBufSize + "/ "+this.recorderBufSize);
this.player = new AudioTrack(AudioManager.STREAM_MUSIC,
this.recordingSampleRate, AudioFormat.CHANNEL_OUT_MONO, audioFormat,
this.recorderBufSize, AudioTrack.MODE_STREAM);
this.recorder = rec;
this.player.stop();
this.player.flush();
this.player.setPlaybackRate(this.recordingSampleRate);
return;
}
}
} catch (IllegalArgumentException e) {
Log.d(LOG_TAG, this.recordingSampleRate + "Exception, keep trying.", e);
} catch (Exception e) {
Log.e(LOG_TAG, this.recordingSampleRate + "Some Exception!!", e);
}
// for loop for channel config ended here. . . .
// for loop for audioFormat ended here. . .
// }// for loop for sampleRate
return;
}
private void startPlaying() {
LOG_TAG = "startPlaying";
Log.e(LOG_TAG, "start Playing");
}
private void stopPlaying() {
LOG_TAG = "stopPlaying";
Log.e(LOG_TAG, "stop Playing");
}
private void startRecording() {
LOG_TAG = "startRecording";
/* start a separate recording thread from here . . . */
startRecThread = new Thread() {
@Override
public void run() {
// TODO Auto-generated method stub
android.os.Process
.setThreadPriority(android.os.Process.THREAD_PRIORITY_URGENT_AUDIO);
// String LOG_TAG = Thread.currentThread().getName();
if(recorder.getRecordingState() != AudioRecord.RECORDSTATE_RECORDING){
recorder.startRecording();
}
// Log.e(LOG_TAG, "running" +recorder.getRecordingState());
while (recorder.getRecordingState() == AudioRecord.RECORDSTATE_RECORDING) {
recorder.read(audioData, 0, audioData.length);
try {
Thread.sleep(1000); // sleep for 2s
} catch (InterruptedException e) {
// TODO Auto-generated catch block
Log.e("run Method", "recorder thread is interrupted");
e.printStackTrace();
}
}
}
};
setVolumeControlStream(AudioManager.STREAM_MUSIC);
audioManager.setSpeakerphoneOn(false);
player.flush();
player.play();
startRecThread.start();
Log.e(LOG_TAG, "start Recording");
}
private void stopRecording() {
LOG_TAG = "stopRecording";
recorder.stop();
if (startRecThread != null && startRecThread.isAlive()) {
startRecThread.destroy();
startRecThread = null;
}
player.stop();
player.flush();
Log.e(LOG_TAG, "stop Recording");
}
private void stop() {
if (isRecording) {
isRecording = false;
stopRecording();
}
if (isPlaying) {
isPlaying = false;
stopPlaying();
}
recordBtn.setEnabled(true);
playBtn.setEnabled(true);
}
@Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
LOG_TAG = "onCreate";
// Log.e(LOG_TAG, "Create Called");
// getting the audio service
audioManager = (AudioManager) getSystemService(AUDIO_SERVICE);
LinearLayout ll = new LinearLayout(this);
// creating Buttons one by one . . . .
// button to start the recording process
recordBtn = new Button(this);
recordBtn.setText("Record");
recordBtn.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
recordBtn.setEnabled(false);
playBtn.setEnabled(false);
isRecording = true;
startRecording();
}
});
// single button to stop recording and playing as applicable
stopBtn = new Button(this);
stopBtn.setText("Stop");
stopBtn.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
stop();
}
});
// button to play the recorded sound
playBtn = new Button(this);
playBtn.setText("Play");
playBtn.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
// reverse the isPlaying
isPlaying = true;
recordBtn.setEnabled(false);
playBtn.setEnabled(false);
startPlaying();
}
});
ll.addView(recordBtn, new LinearLayout.LayoutParams(
ViewGroup.LayoutParams.WRAP_CONTENT,
ViewGroup.LayoutParams.WRAP_CONTENT, 1));
ll.addView(playBtn, new LinearLayout.LayoutParams(
ViewGroup.LayoutParams.WRAP_CONTENT,
ViewGroup.LayoutParams.WRAP_CONTENT, 1));
ll.addView(stopBtn, new LinearLayout.LayoutParams(
ViewGroup.LayoutParams.WRAP_CONTENT,
ViewGroup.LayoutParams.WRAP_CONTENT, 1));
setContentView(ll);
}
@Override
protected void onDestroy() {
// Clean up code . ..
super.onDestroy();
if (recorder != null)
recorder.release();
if (startRecThread!=null && startRecThread.isAlive())
startRecThread.destroy();
if (recorder != null)
recorder.release();
if (player != null)
player.release();
startRecThread = null;
recorder = null;
player = null;
recordBtn = null;
stopBtn = null;
playBtn = null;
audioData = null;
System.gc();
}
}
正如您可能会看到startPlaying()和stopPlaying()函数尚未实现，所以不要谈论它们。目前我只是想录制和播放。当我运行程序它播放录制的音频但音频出现在远处。另一个问题是应用程序的 UI线程挂起虽然我有一个单独的线程来读取音频。请帮帮....
答案 0 :(得分：21)
如果您的要求是在录制时它应该播放（意味着循环播放音频），在您的while循环线程中，您正在存储录制的数据（audioData bufer），在那里您可以将其复制到播放器对象中while循环（player.write（audioData，0，numShortsRead）;）。你说你的UI线程卡住了，可能是因为你给予音频记录线程更多的优先权。
检查以下用于上述环回要求的代码
boolean m_isRun=true;
public void loopback() {
// Prepare the AudioRecord & AudioTrack
try {
buffersize = AudioRecord.getMinBufferSize(SAMPLE_RATE,
AudioFormat.CHANNEL_CONFIGURATION_MONO,
AudioFormat.ENCODING_PCM_16BIT);
if (buffersize <= BUF_SIZE) {
buffersize = BUF_SIZE;
}
Log.i(LOG_TAG,"Initializing Audio Record and Audio Playing objects");
m_record = new AudioRecord(MediaRecorder.AudioSource.MIC,
SAMPLE_RATE, AudioFormat.CHANNEL_CONFIGURATION_MONO,
AudioFormat.ENCODING_PCM_16BIT, buffersize * 1);
m_track = new AudioTrack(AudioManager.STREAM_ALARM,
SAMPLE_RATE, AudioFormat.CHANNEL_CONFIGURATION_MONO,
AudioFormat.ENCODING_PCM_16BIT, buffersize * 1,
AudioTrack.MODE_STREAM);
m_track.setPlaybackRate(SAMPLE_RATE);
} catch (Throwable t) {
Log.e("Error", "Initializing Audio Record and Play objects Failed "+t.getLocalizedMessage());
}
m_record.startRecording();
Log.i(LOG_TAG,"Audio Recording started");
m_track.play();
Log.i(LOG_TAG,"Audio Playing started");
while (m_isRun) {
m_record.read(buffer, 0, BUF_SIZE);
m_track.write(buffer, 0, buffer.length);
}
Log.i(LOG_TAG, "loopback exit");
}
private void do_loopback() {
m_thread = new Thread(new Runnable() {
public void run() {
loopback();
}
});
还有一件事，如果你的要求是记录几秒然后播放，当它正在播放你的记录时应该重新开始，你可以用一个带有超时的延迟处理程序线程做到这一点，在那个线程你可以停止录制复制缓冲区，然后开始录制。
答案 1 :(得分：3)
我的建议是使用其他称为无痛线程的异步任务。这是利用Android中线程的最佳方式。您可以通过划分现有程序来使用后台处理，预执行和后执行方法。
http://android-developers.blogspot.ca/2009/05/painless-threading.html